Belt locking device for a vehicle seat

ABSTRACT

In a belt locking device for a vehicle seat, in particular a motor vehicle seat, having a moveably attached belt lock ( 19 ), a tightening unit ( 13 ) supported on a structure-fixed support element ( 29 ), and a transmission means ( 21 ) acting between the tightening unit ( 13 ) and the belt lock ( 19 ), wherein, in the event of a crash, the tightening unit ( 13 ) pulls the belt lock ( 19 ) from an initial position into a crash position by means of the transmission means ( 21 ), the position of the tightening unit ( 13 ) can be changed in a longitudinal direction of the transmission means ( 21 ) relative to the support element ( 29 ).

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a continuation of International Application PCT/EP2004/005632, which was filed May 26, 2004. The entire disclosure of PCT/EP2004/005632, which was filed May 26, 2004, is incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to a belt locking device for a vehicle seat, in particular a motor vehicle seat, with the belt locking device having a moveably attached belt lock, a tightening unit supported on a structure-fixed support element, and a transmission means acting between the tightening unit and the belt lock, wherein, in the event of a crash, the tightening unit pulls the belt lock from an initial position into a crash position by means of the transmission means.

In a belt locking device of the type discussed immediately above, when there is a wide middle console between the vehicle seats, there exists the problem that a belt lock that is in a low position for optimum belt run can be poorly accessible.

BRIEF SUMMARY OF SOME ASPECTS OF THE INVENTION

An aspect of the present invention is the provision of improvements to a belt locking device of the type mentioned above. In accordance with one aspect of the present invention, a belt locking device for a vehicle seat, in particular a motor vehicle seat, has a moveably attached belt lock, a tightening unit supported on a structure-fixed support element, and a transmission means acting between the tightening unit and the belt lock, wherein, in the event of a crash, the tightening unit pulls the belt lock from an initial position into a crash position by means of the transmission means, and wherein the position of the tightening unit can be changed in a longitudinal direction of the transmission means relative to the support element.

By providing means to change the position of the tightening unit relative to the support element in the longitudinal direction of the transmission means, it is possible to provide, in addition to the belt tightening function, a comfort position that is more extended in comparison with the initial position of the belt lock, and in which the belt lock is more easily accessible. Once the passenger has put on the seatbelt, the belt lock returns to its initial position. By changing the position of the tightening unit, the belt lock is moved by means of the transmission means, i.e. the belt lock, tightening unit and support element are in series with respect to the force load occurring during tightening and when the belt is under functional load, i.e. a serial solution has been realized for both situations in which the belt is tightened (comfort and crash). As a rule, the transmission means is tension and pressure proof and flexible, with the option of a spring or another energy storage means keeping the belt lock in an upright position.

The position of the tightening unit can preferably be changed by means of a motor, i.e. the tightening unit is driven by a motor, on the one hand, in order to define a specific movement and, on the other hand, to increase comfort. To protect the support element of the tightening unit from dirt and damage, it is preferably located in a structure-fixed casing which also houses the motor and in which the belt lock is supported for example through a deflector and the spring. Fixing the casing to the structure can be realized with e.g. the seat frame, the upper rail, the lower rails or the vehicle structure.

In a preferred embodiment, the support element is in the form of a motor-driven rotatable spindle nut supported inside the casing, into which is screwed a spindle, the rotation of the motor being translated into a shifting of the tightening unit with simultaneous gear reduction. The spindle can be part of the tightening unit, i.e. of the tightening casing or, optionally, can be an independent element bearing against the tightening casing or being attached to it. In order to save construction space, the transmission means is preferably led through the spindle, which would then have to be hollow (e.g., define a passageway).

The invention is applicable to all vehicle seats having a belt tightener. Depending on the control and available sensors, different situations such as, for example, sitting down, opening the door, turning off the engine, or crash, may cause the comfort position to be assumed.

Other aspects and advantages of the present invention will become apparent from the following.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is explained in more detail with reference to an exemplary embodiment which is illustrated in the drawings, in which:

FIG. 1 is a section through the exemplary embodiment in the comfort position,

FIG. 2 is a lateral view of the exemplary embodiment in the initial position,

FIG. 3 is a lateral view of the exemplary embodiment in the comfort position,

FIG. 4 is a lateral view of the exemplary embodiment in the crash position,

FIG. 5 is a schematic lateral view of a vehicle seat, and

FIG. 6 is a section through the exemplary embodiment in the original position.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENT

A belt locking device 1 for a vehicle seat 3 of a motor vehicle is fixed to the structure of the vehicle seat 3 on the side of the seat 3 that is adjacent to the vehicle's center tunnel. The purpose of the belt locking device 1 is to releasably attach a safety belt 5 of the vehicle seat 3. The arrangement of the vehicle seat 3 within the vehicle and the vehicle's normal direction of travel define the following directional indications. The belt locking device 1 has an oblong casing 11 whose longitudinal direction aligns with the direction of travel, and a pyrotechnical tightening unit 13 that is moveable in the direction of travel, is partly arranged inside the casing 11, and is otherwise protruding frontward. The belt locking device 1 furthermore has a deflector 15 arranged at the rear end of the casing 11, a spring 17 in the form of a helical spring pointing obliquely away from the deflector 15 frontward, and a belt lock 19 arranged at the upper end of the spring 17 for receiving the belt tongue of the safety belt 5.

A traction and pressure proof, flexible transmission means 21, in the present case a steel cable, is run from the tightening unit 13 backward and obliquely upward via the deflector and through the spring 17 towards the belt lock 19, and is attached to the belt lock 19. The transmission means 21 thus acts between the tightening unit 13 and the belt lock 19. The transmission means 21 is attached so that it can move in the longitudinal direction of the transmission means 21 relative to the casing 11, and flexibly transversally to the casing 11. The spring 17 is enclosed in bellows 23 that extends between the belt lock 19 and the deflector 15. The bellows 23 provides protection from dirt and other external effects. A motor 25 is supported in the casing 11. The motor 25 is in gear connection with a spindle nut 29 by means of a spur gear 27. The spindle nut 29 is screwed onto a non-rotating, hollow spindle 31 forming a rear part of the tightening unit 13 and through which the transmission means 21 is running towards the rear. The spindle nut 29, which is rotatably supported in the casing 11, acts as a support element for the tightening unit 13. In the initial position, the rear end of the spindle 31 is located at least approximately within the spindle nut 29.

In the event of a crash, the belt locking device 1 executes the known belt tightening function, i.e. the tightening unit 13 ignites and a part thereof rushes forward—supported on the part that is connected to the spindle 31 and pulling the belt lock 19 downward by means of the transmission means 21, against the force of the spring 17. This crash position is shown in FIG. 4. The safety belt 5 being locked in the belt lock 19 is tightened, i.e. a possible looseness in the belt is removed, so that the passenger is moved forward as little as possible.

The belt locking device 1 also has a comfort function because of a change in the position of the tightening unit 13. When a passenger sits down on the vehicle seat 3, this event being registered by the seat occupation recognition sensors, the motor 25 is activated, pushing the spindle 31 backward by means of the spindle nut 29. The tightening unit 31 that is carried along also moves the transmission means 21 backward, so that the spring 17 can use the freed path to extend the belt lock 19, as is shown in FIG. 3. The belt lock 19 thus becomes more easily accessible for the passenger. As soon as the safety belt 5 is completely buckled, the motor 25 moves the spindle 31 forward, i.e. it again pulls in the belt lock 19, until the optimal belt run is achieved and the looseness of the belt has been removed.

In a “postsafe”-able variation, after the crash the belt lock 19 is also brought into the comfort position by means of the motor 25, if this is still possible, in order to give rescuers easier access to the passenger.

It will be understood by those skilled in the art that while the present invention has been discussed above with reference to an exemplary embodiment, various additions, modifications and changes can be made thereto without departing from the spirit and scope of the invention as set forth in the following claims. 

1. A belt locking device that is for a vehicle seat and operates advantageously in response to a crash, the belt lock device comprising: a tightening unit supported by a support element and operatively connected to a belt lock by way of a transmission means, wherein (a) the tightening unit is operative for pulling the belt lock, by way of the transmission means, from an initial position into a crash position in response to the crash, and (b) the tightening unit is mounted for moving relative to the support element in a longitudinal direction of the transmission means; and a motor operatively associated with the tightening unit for moving the tightening unit relative to the support element in the longitudinal direction of the transmission means, so that the belt lock is moved by way of the transmission means.
 2. The belt locking device according to claim 1, wherein the transmission means is tension stable and/or pressure stable and/or flexible.
 3. The belt locking device according to claim 1, further comprising a casing that is for being fixedly mounted, wherein the support element is supported in the casing.
 4. The belt locking device according to claim 3, wherein the motor is arranged inside the casing.
 5. The belt locking device according to claim 1, further comprising a casing, wherein: the tightening unit includes a spindle, the spindle is rotatably supported in the casing, the support element is a spindle nut, the spindle nut is screwed onto the spindle, and said operative association between the motor and the tightening unit comprises the motor being operative for driving the spindle nut.
 6. The belt locking device according to claim 1, further comprising a casing and a spindle, wherein: the spindle is rotatably supported in the casing, the support element is a spindle nut, the spindle nut is screwed onto the spindle, and said operative association between the motor and the tightening unit comprises the motor being operative for driving the spindle nut.
 7. The belt locking device according to claim 6, wherein said operative association between the motor and the tightening unit further comprises the spindle being operatively associated with the tightening unit for moving with the tightening unit in response to the motor driving the spindle nut.
 8. The belt locking device according to claim 1, wherein the belt lock, the transmission means, the tightening unit and the support element are in series with respect to forces occurring while the transmission means is under tension.
 9. The belt locking device according to claim 1 in combination with the vehicle seat.
 10. The combination according to claim 9, wherein the belt locking device further comprises a casing that is fixedly mounted to the vehicle seat, and the support element is supported in the casing.
 11. The belt locking device according to claim 5, wherein the spindle nut and the motor are arranged inside the casing.
 12. The belt locking device according to claim 6, wherein the spindle nut and the motor are arranged inside the casing.
 13. The belt locking device according to claim 1, wherein the tightening unit is a pyrotechnical tightening unit.
 14. The belt locking device according to claim 2, wherein the belt lock, the transmission means, the tightening unit and the support element are in series with respect to forces occurring while the transmission means is under tension.
 15. The belt locking device according to claim 3, wherein the belt lock, the transmission means, the tightening unit and the support element are in series with respect to forces occurring while the transmission means is under tension.
 16. The belt locking device according to claim 4, wherein the belt lock, the transmission means, the tightening unit and the support element are in series with respect to forces occurring while the transmission means is under tension.
 17. The belt locking device according to claim 5, wherein the belt lock, the transmission means, the tightening unit and the support element are in series with respect to forces occurring while the transmission means is under tension.
 18. The belt locking device according to claim 1, wherein the transmission means comprises a cable.
 19. The belt locking device according to claim 5, wherein the spindle defines a passageway extending therethrough, and the transmission means extends through the passageway.
 20. The belt locking device according to claim 6, wherein the spindle defines a passageway extending therethrough, and the transmission means extends through the passageway.
 21. The combination according to claim 9, wherein the motor being operatively associated with the tightening unit for moving the tightening unit relative to the support element in the longitudinal direction of the transmission means, so that the belt lock is moved by way of the transmission means, comprises: the motor being operative, in response to a user sitting on the vehicle seat, for automatically moving the tightening unit relative to the support element in the longitudinal direction of the transmission means, so that the belt lock is moved upward by way of the transmission means.
 22. The belt locking device according to claim 1 in combination with a safety belt, wherein the motor being operatively associated with the tightening unit for moving the tightening unit relative to the support element in the longitudinal direction of the transmission means, so that the belt lock is moved by way of the transmission means, comprises: the motor being operative, in response to the safety belt being buckled to the belt lock, for automatically moving the tightening unit relative to the support element in the longitudinal direction of the transmission means, so that the belt lock is moved downward by way of the transmission means. 